California Oregon Intertie (COI), identified as Path 66 by Western Electricity Coordinating Council (WECC), is a corridor of three roughly parallel 500 kV alternating current power lines connecting the electric grids of Oregon and California. Their combined power transmission capacity is 4800 MW. Two of the power lines run from Malin Substation southeast of Klamath Falls, Oregon to Round Mountain Substation northeast of Redding, California. One of them is owned by Western Area Power Administration, the other by Pacific Gas and Electric and PacifiCorp jointly. These lines are a part of Pacific AC Intertie and were completed in the 1960s. The third line runs from Captain Jack Substation near Malin to Olinda Substation south of Redding. It is a part of California-Oregon Transmission Project, the project manager is the Transmission Agency of Northern California (TANC), a joint venture of several public utilities. It was completed in 1993. Route Path 66 is composed of one segment of TANC, PG&E and PacifiCorp 500 kV lines. The TANC line route starts at Captain Jack Substation (42° 4' 38.06"N 121° 23' 25.47"W) close to Malin, close to the California-Oregon border, near the Malin Substation, where the other 500 kV lines start (PacifiCorp & PG&E). These substations link to both the PacifiCorp and Bonneville Power Administration (BPA) grid in the Pacific Northwest. Path 66 - Captain Jack to Olinda Path 66 consists of the northernmost segment of TANC's 500 kV line from Captain Jack substation to Tracy substation in California's Central Valley. Leaving Captain Jack substation, the line first heads southeast as a single-circuit line and runs parallel with the other two 500 kV lines across the Modoc Plateau. It then turns west and climbs in elevation and reaches its highest point near Grizzly Peak at about . From there, it heads south, spanning over the Stonecoal Valley and the Pit River. Near Round Mountain, it turns southwest and the line is joined by two 230-kV lines as all three lines head into the Sacramento Valley. As the line passes by Cottonwood, it turns west and crosses Interstate 5. Near Olinda, it turns south and enters Olinda substation. Here the line interconnects with transmission lines carrying power from Shasta Dam and Keswick Dam. Connecting wires to Path 15 - Olinda to Tracy From Olinda Substation, the TANC 500 kV continues as a single-circuit line, although the tower structures change (see photos below) to a two-level